org.apache.cocoon.portal.event
Interface EventManager

This component manages the event handling mechanism in the portal.
The event mechanism is based on the publisher/subscriber principle.
An interested component (a Receiver
can subscribe itself for a specific class (or classes) of events.
All Events have a common ancestor type Event and the event types are
identified by a (sub)class
The old design which is now deprecated has been inspired by the paper by
Gupta, S., J. M. Hartkopf, and S. Ramaswamy, in Java Report, Vol. 3, No. 7, July 1998, 19-36,
"Event Notifier: A Pattern for Event Notification".
EventManager brokers events between a Publisher, which produces events,
and a Subscriber, which handles the notification of events.
A Filter discards events not of interest to a subscriber.